<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        div{
            box-sizing: border-box;
        }
        .container{
            width:1240px;
            height:400px;
            margin-left: auto;
            margin-right: auto;
            display:flex
        }
        .container>div{
            flex:1;
            height:400px;
            border:1px solid #333;
            margin-left: -1px;
        }
    </style>
</head>
<body>
        <div class="container">
                <div class="one"></div>
                <div class="two"></div>
                <div class="three"></div>
                <div class="four"></div>
            </div>
</body>
</html>